1. Field of the Invention
The present invention relates to a power converter for a fuel battery.
2. Description of Related Art
A fuel battery is a type of new power supply that is of high efficiency and low pollution. The fuel battery can supply 48V and over 100 A power to a loading. When using the fuel battery as the power supply, it requires a full-bridge inverter, a transformer and a rectifier between the fuel battery and the loading to process the transform of the electrical characteristics. As shown in FIG. 1, the conventional power converter 10 that can provide electrical transform of 5 KW comprises a full-bridge inverter 12, a transformer 16, and a rectifier 18. Moreover, the full-bridge inverter 12, the transformer 16, and the rectifier 18 are connected in sequence to form the power converter 10. The power converter 10 can process the transform of electrical characteristics of the power from the fuel battery 20. For example, it can convert the 48V direct current into 400V direct current to provide the power consumption of loading 30.
Due to the power transistor 13 of the full-bridge inverter 12 not being able to pass a peak drain current over 70 A, every switching circuit 14 adopts two parallel power transistors 13 to reduce or balance the drain current that every power transistor 13 needs to pass. The two parallel power transistors 13 also alternatively enable/disable the switching circuit 14 to provide the power transistors 13 sufficient time for radiating the heat to avoid the depreciation of the full-bridge inverter 12 due to excessive heat.
However, the conventional power converter 10 has the following defects: the volumes of a filtering capacitor C1 of the full-bridge inverter 12, power transistors 13, transformer 16, filtering inductance L1 and filtering capacitor C2 of the rectifier 18 are all non-reducible which will cause the limitation of the application of the power converter 10.
Therefore, it is desirable to provide a power converter for a fuel battery to alleviate or mitigate the aforementioned problem.